SAP Message ACO401 - Substitutes for '&1' have already been changed by another user

Diagnosis
You entered or deleted substitutes for '&V1&' and want to save thechanges. However, these substitutes have meanwhile been changed and thensaved by one or more other users.

System Response
The system does not allow you to save the changed substitutes for '&V1&'and discards the changes you made because they are based on data that isno longer up-to-date. Moreover, the updated substitutes for '&V1&' arebeing loaded.

Procedure
Check the updated substitutes for '&V1&' and change them if this isstill necessary.